The present invention relates to a tamper-resistant display holder having a magnetically attractable tab which locks and unlocks a front member of the holder relative to a back member of the holder.
Display holders and frames are used for replaceable posters, pictures and similar advertising materials. Display holders are used in various public and private areas such as buses, taxicabs, store fronts, floor stands and other advertising locations. Display holders are preferably constructed such that the advertising materials can be easily replaced but not tampered with or stolen, particularly when the display holder is used in a public area.
An example of a tamper-proof display holder of the prior art is a locked box, such as that disclosed in U.S. Pat. No. 4,763,428, which has a window through which the advertising materials can be viewed. The locked box requires a key to be opened. The locked boxes of the prior art are typically expensive, cumbersome and unattractive.
A variety of more streamlined and economical spring-loaded display holders have been developed in which the advertising materials are interchangeable by hand. For example, U.S. Pat. No. 3,310,901 discloses a display holder having a plurality of frame sections. Each section includes two extruded portions which are interconnected with one another in a pivotal relationship. A metal leaf spring biases the extruded portions together to releasably clamp posters or similar display items in the frame. One of the extruded portions includes a lip that can be grasped to open or close the frame section. The display holder can therefore be readily tampered with.
U.S. Pat. No. 4,519,152 discloses a display holder having frame sections with smooth surfaces and rounded, non-convoluted corners such that the frame sections cannot be easily gripped with enough frictional force to open the frame. An opener tool with a lever arm is disclosed for engaging the front portion of the frame to open the display holder. The disclosed display holder is not entirely tamper proof, however, since the frame can be pried open with any handy tool, such as a pen or a knife.